Method of producing paper drum containers



Sept. 18, 1951 A. L. SCOTT METHOD OF PRODUCING PAPER DRUM CONTAINERSFiled Oct. 16, 1947 2 Sheets-Sheet 1 Arthur L. Scott Sept. 18, 1951 LSCOTT METHOD OF PRODUCING PAPER DRUM CONTAINERS Filed Oct. 16, 1947 2Sheets-Sheet 2 Y7 ig u,

i 8 gvwmvtm Ar Thur L. Scofi odsof making the same.

cerned with a container, the walls of'which com- Patented Sept. 18, 1951OFFICE METHOD OF PRODUCING PAPER DRUM CONTAINERS Arthur L. Scott,Columbus, Ohio Application October 16, 1947, Serial No. 780,173

2 Claims.

This invention relates to containers andmeth- In particular, it is conweight and ability to withstand abuse in handling and shipping. Thelatter advantage, how- 1 ever, has heretofore been greatly lessened inthe case of cylindrical containers becauseof the diificulty in producinga truly strong bond between the container wall and the end closures. Thejoint btween the wall and an end piece is in- Itrinsically a point ofweakness because it occurs at both a discontinuity in the contour and adiscontinuity in material. abrupt corner must usually be retainedbecause While the more or less of the practical necessity for flat endsupon which the container may stand or with which it may I abut itsneighbors in the saving of storage space,

the ideal construction would be one in which the material of the wallpassed continuously into that of the end. Not only would maximum'strength he thus obtained but also economy in the avoidance offastening devices such as crimping bands.

"The primary object of the present invention,

therefore, is to provide a cylindrical container having integral sideand end walls.

Another object is to provide a method of mak- "ing sucha containerwithout waste of material,

the blanks for two containers or for a container and its removable capbeing complementary in outline and thus derivable from a single strip.

Still another object is to provide a construction for such a containerwhich will render it highly impervious by reason of multiple overlappingof its elements.

These objects I accomplish by means of a blank having a serrated edge.The serrations take the form of elongated triangular tabs withtriangular notches therebetween, the length of the triangular tabsequalling the radius of the finished container. The blank is wound upona mandrel of the desired size with the tabs projecting beyond it. Thetabs are then bent inwardly against Y the mandrel end, preferably in aprogressive 7 fashion as they reach the mandrel in the winding process.

The width of the tab bases is so chosen that a large number of them, saytwenty to twenty-five,

occur on the container circumference, whereby the distortion in bendingover the arcuate edge joining wall.

is minimized. The tabs reach to the center and lie in an edge-to-edgefashion as segments of the circle. When a complete turn has been madeupon the mandrel, the end is completely covered by the tabs, the lasttab being more than sufiicient and thus overlapping the first. Due tothis initial overlap, each tab of the new layer overlies a junction inthe preceding layer and as the wind-'- ing progresses a completelyimpervious structure results.

Both the zone of weakness where the sharp points of the tabs meet at thecenter and the tendency of the tabs to retreat from the center due tothe increase in radius as the winding progresses are attended to in asimple and effective manner. A plurality of discs, of the same materialas the blank, are interposed between the various layers of tabs. Where aflat outer surface is desired, a recess is formed in the mandrel end toaccommodate the increased number of thicknesses. The length of tab is sochosen that the points of the outer layer meet at thecenter. The pointsof the inner layers would overlap the center by progressively greateramounts, due to the decreasing radius of the turns on the mandrel, if itwere not for the fact that they need to bend progressively deeper intothe recess as the number of discs increases. This number may be sochosen that the compensation is practically exact.

It will be understood that some form of bonding occurs between thelayers. The stockmay be impregnated with a thermoplastic orthermosetting material and appropriately treated during the formation orafter completion of the container, or a simple adhesive may be appliedas the stock approaches the mandrel.

Wastage of stock is eliminated since the serrating produces two blanks,each having triangular tabs and notches, which are bothusable.

In the drawings,

""Fig. 1 is a diagrammatic perspective view illus- 'tratin'g' a methodof making a container and a closure therefor;

- Fig. 2 is a bottom plan of a container;

Fig. 3 is a sectional view taken on the plane of Fig. 2;

Fig. 4 is a plan of a serrated strip showing the two blanks derivabletherefrom;

Fig. 5 is a perspective view of a closure or container cap madeaccording to this invention;

Fig. 6 is a similar view of a container;

Fig. 7 is a longitudinal, medial section of a container illustrating thecontour but omitting the fine structure of the wall and end; and

Fig. 8 is an enlarged radial section showing the structure of part ofthe container end and ad- In the drawings, a preferred form of mycontion of thetedges.

. terlocked pattern -of Fig. '3.

h completion of each convolution. "on the outer surface to prevent thelifting of the outer set of tips.

' among the various convolutions. vided, in the mandrel end, ofsufilcient depth to accommodate the added thickness of the discs.

tainer is illustrated, along with an indication of From the dies theblanks are led to mandrels" or forms and 2|. In the set-up shown in Fig.1 a container and its caparebeing simultaneously produced. Accordingly,the form 2| is sufilciently larger in diameter than the form 20 toproduce the desired fit of the finished parts.

The winding of the strips is done atthe end of the mandrels whereby theserrations l! are allowed to overhang. The latter are then bent attheedgeof the form, all at one time at the --completion of the winding or,preferably, progressively as the reach the mandrel.

The triangular portions are so proportioned that they fit together inedge-to-edge relationship as segments of the circular end.Theoretically, of course, itis not possible to form the arcuate bases ofthe segments, using a fiat material, but in, practice, where asumciently large number of segments are used, the bulging at the cornersis hardly perceptible and is flattened downbysucceedinglayers.Similarly, the theoretical impossibility of having identical trianglesproduce segments of increasingly larger circles as the windingprogresses is resolved in practice by 'a barely perceptible overlap oraminute separa Here, again,.succeeding layers cover all discrepancies. H

The segments pertaining to a given convolutionof the wall strip overliethe juxtaposed edges of those pertaining tothe preceding convolution.This salutoryeffect i-s-obtained by having the in- "terval or spacingbetween successive serrations a non-aliquotpa-rt of the cylindercircumference. 'This is illustrated inFig. 2where it is evident that all.segments after'the twenty-third will close the joints below them,resulting in .the in- It willbe evident thatthe joints in every secondlayer are'prevented from coinciding by the increasing circum-f erence.

To close any opening which may be left at the center and to reinforcethe slender tips of the segments, it is' preferable to apply discs 25,

- usuall'y'of the same material, which are of sufficient size to coverthe zone'of weakness. Any appropriate number of discs may be included,depending upon the material usedand the service to "which the containeris to be put. In the average type of container it is preferable 'tostart with a disc, which will 'thusrbe on the inner-surface to pr'eventthe liftingof the inner set of tips, and then to add an additional oneat the This tplacesione As shown in Fig. l, the discs'may be secured, byan appropriate applicator not shown, to the tips of individualserrations before they reach the mandrel. As these serration aresubsequently -bent into positionthe discs assume their pro-per place atthe center.

Figs. '7 and 8 illustrate the action of the discs in compensating forthe change in radius A recess is'pro- I flat outer surface.

'4 I as illustrated at 26. The inner disc 25 enters the recess and thefirst set of segments l1 bend axially inwardly to lie thereon. As thenumber of discs increases, succeeding sets of segments are bent tolesser degrees. Because the segments are drawn radially outwardly to anincreasing extent by theenlarging bend at 21, their inner 'tipscan bemade to remain' practically at the center 28. The outer disc 25" thencompletes the assembly and forms a continuation of the -A'spreviously'mentioned, any appropriate form of 'bondingmay be used tobind the layers. Thestrip'may, for example be passed through andimpregnating bath, not shown, or may have an adhesive'coated'thereon, asby applicators indicated at 30 in Fig. 1.

A container made according to my invention is illustrated in Fig. 6, anda cap therefor in Fig. 5.

The method is'particularly well adapted to the production of the largersizes of *containerasay 10 gallons to 50 gallons, and results in a verydurable article. As an example may be mentioned-a test specimen, made oflaminations of kraft paper, which was filled with 70 pounds of sand andthen shipped by express and motor freight onseven round trips totalling2,850 miles. Be

spite the severe abuse which this entailed, the

container. remained structurally sound.

'While 'Ihave shown and described asingle embodiment of my container itwill be evident that the method may be extended to the .produc-' tion ofvarious forms and modifications of that shown.

I claim:

1. A method of making a container comprising, serrating a strip ofmaterial, securing reinforcing-.discsto some ofthe serrations, windingthe unserrated portion on a cylindrical .form, bending the serrationsradially inwardly to produce a closedend and to cause the. discs tooverlie portions of preceding serrations, and. causing continguouslayers of material to adhere.

2.. A'method of making acylindrical container and .closure thereforcomprising, longitudinally serrating astrip of material to produce afirst strip having triangular extensions approximately equal in lengthto the container radiusand-an unserrated width equal to the containerlength and, a second strip having similiar extensions and. an unserratedwidth equal to the closure length, winding the strips on cylindricalforms having container and closure diameters respectively, bending theextensions radially inwardly to produce closed ends, and causingcontinguous layers of material to adhere.

' ARTHUR L. SCO'I'I.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 192,727 Switzerland Nov. 16, 1937

